A fuse assembly is known in the art, for example, as disclosed in Japanese Patent No. 4,238,783, which discloses a structure for a fuse mounting portion of an electric connector box, to which fuse sub-assemblies are mounted. According to the structure for the fuse mounting portion of the above prior art, it is possible to mount two kinds of fuse sub-assemblies to the electric connector box, wherein outer dimensions of the fuse sub-assemblies in a fuse-insertion direction (more exactly, a length in a height direction of the fuse sub-assembly) are different from each other. A pair of ribs is provided in a cavity of a housing for the electric connector box in a width direction of the cavity, wherein each of the ribs is projecting into an inside of the cavity. An upper end surface of each rib, namely an end surface of the rib on a side to an opening end of the cavity, is inclined with respect to the fuse-insertion direction.
When the fuse sub-assembly is inserted into the cavity, a stepped portion of the fuse sub-assembly is brought into contact with the inclined surfaces of the ribs, so that the fuse sub-assembly is positioned in the fuse mounting portion.
The housing of the electric connector box of the above prior art is generally made of resin. When thermal shock is applied to the housing made of resin, the fuse mounting portion is thermally expanded or contracted. Then, a relative positional relationship between the ribs and female terminals (made of, for example, copper alloy) provided in the cavity may be changed. For example, when the cavity is thermally expanded, the fuse sub-assembly is pushed in the width direction of the cavity (perpendicular to the fuse-insertion direction) by the inclined surface of the rib.
As a result, the fuse sub-assembly is relatively moved in the cavity whenever the thermal expansion and contraction are repeated in the cavity. In other words, sliding movement of a male terminal with respect to the female terminal is repeatedly carried out in the cavity. As a result, contact failure is likely to occur between the male terminal and female terminal provided in the cavity due to abrasion powder of the terminals and/or decrease of contact pressure between the terminals. When the contact failure occurs in the fuse sub-assembly, voltage drop may occur at the terminals of the contact failure and operation of an electric or electronic devices connected to the fuse sub-assembly may be adversely affected due to such voltage drop.